1. Field of the invention
The present invention relates to an electrical connector, and more particularly to an electrical connector having contacts disposed radially for creating different pitches to interconnect an electronic package and a printed circuit board.
2. Description of Related Art
U.S. Pat. No. 7,044,746 issued to Copper et al. on May 16, 2006 discloses an electrical connector mounted on a printed circuit board for receiving an electronic package. As typically shown in FIGS. 1 and 3 of original disclosure, the electrical connector includes an insulative housing with a plurality of contacts received therein. The contacts are arranged in a matrix of high density, and each contact has two ends to respectively contact with a pad of the electronic package and another pad of the printed circuit board, so that the electrical connection between the electronic package and the printed circuit board is established. As a higher desire for the performance of the electronic package, the number of the pads of the electronic package and the contacts of the electrical connector are increased in the predefined area. However, as the number of the contacts of the electrical connector is increased, the risk of short circuit of neighboring contacts is substantially increased when the contacts are soldered onto the pads of the printed circuit board.
To overcome the above disadvantages, Taiwanese Utility Pat. No. M365569 issued to Cheng et al. on Sep. 21, 2009 discloses an improved electrical connector which has a plurality of contacts arranged in a matrix. Each contact has a slantwise neck above a soldering portion which is to be soldered on a printed circuit board. The angles of the necks relative to an imaginary plumb line vary in sequence, as can by typically see from FIG. 4 of original disclosure. For details disclosing the structure of the contacts, the necks at the opposite ends in a row have largest angles relative to the plumb line, and the part near the middle of the row tend to be vertical, so that the lower contact portions are uniformly arranged, while the pitch between any two neighboring soldering portion is larger than the pitch between corresponding two neighboring contact portions located at upper ends of the contacts. However, the contacts featured complicated structure and geometry, the production of the contact is complicated and the cost thereof is increased.
Therefore, an improved fine-pitch electrical connector is desired.